// v2.0
#include <stdio.h>
#pragma once
class ISBNPrefix {
      FILE* fp;
      public:
              ISBNPrefix(const char* filename);
              ISBNPrefix(const ISBNPrefix& source);
              int registered(long area) const;
              int minNoDigits(long area) const;
              int registered(long area, const char* publisher) const;
              ISBNPrefix& operator=(const ISBNPrefix& source);
              ~ISBNPrefix();
};
             
